1. Field of the Invention
The present invention relates to an engine system, especially for vehicles equipped with an engine start-stop automatic system.
2. Description of Related Art
Modern vehicles are equipped with engine systems that have an engine start-stop function. The engine start-stop function is used to shut down the engine, especially when an internal combustion engine is involved, if no torque is to be called for. This applies, above all, if it is to be expected that the torque will not be requested for a certain period of time. If the internal combustion engine according to this engine start-stop function has been shut down, in the case of requests for a drive torque, the internal combustion engine starts automatically, without the driver of the vehicle having to give a start instruction, such as by turning the ignition key, to start the internal combustion engine.
The engine start-stop function is used to save fuel, and therewith particularly to reduce the CO2 emissions. However, shutting down the internal combustion engine and, above all, switching on the internal combustion engine leads to an increased stress on engine components subject to wear, such as the starter or components in the hydraulic system (fuel injection system) which, as a rule, are designed or constructed for a certain number of working cycles or activations.
Based on the engine start-stop function, under certain circumstances it is possible that a large number of start-stop processes of the internal combustion engine are executed over its lifetime. Because of this, individual components of the internal combustion engine may experience increased stress, and this may even lead to the maximum number of working cycles or activations, specified by the manufacturer, being exceeded. This leads to an increased risk of failure for the respective component and it is consequently able substantially to lower the service life of the internal combustion engine. Increasing the robustness of the respective components leads to greater cost, and is not cost-neutral.